1. Field of Invention
The present invention relates to medicaments for inhibiting thrombus formation.
2. Description of Related Arts
An incidence, morbidity, and mortality of thrombotic diseases such as myocardial infarction and cerebral thrombus formation are among the toppest in a variety of diseases. Stenosis and thrombus formation of Coronary artery or cerebrovascular artery are formed on a basis of atherosclerosis and caused by repeat injury of blood vessels. When the blood vessels are suffered from injury, platelets, which are adhered to to exposed subcutaneous tissue, release contents in the particles thereof which are adenosine diphosphate (ADP), and thromboxane A2 (TXA2) formed from metabolism of membrane phospholipid. These two contents activate platelets which are in the circulation, and the activated platelets are then aggregated to form platelets thrombosis with an existence of fibrinogen. The injury of blood vessels also activates the coagulation system, and the generated thrombin promotes a further aggregation of the platelets and fibrin is subsequently formed, so that stability of arterial thrombus is enhanced after crosslinking with fibrin. Anti-platelet drugs inhibit thrombus formation by inhibiting adhesion, aggregation, and release of the plates, and thus play an important role in prevention and treatment of thrombotic diseases.
Triflusal is a kind of agent for preventing aggregation of platelets and has an extraordinary effect in prevention and treatment of thrombotic diseases and complicating diseases in comparison with acetylsalicylic acid (aspirin), for triflusal is capable of antagonizing activity of cyclooxygenase and c-AMP phosphodiesterase at the same time and has an effective effect for inhibiting aggregation of platelets. In the meantime, triflusal, which is in therapeutic doses, has little influence on biosynthesis of prostacyclin and the risk of bleeding is also a minimum. Studies have shown that there is no difference when triflusal and aspirin are employed to prevent severe cardiovascular events for patients with peripheral arterial occlusive disease (PAOD), but the incidence of complicating diseases when using triflusal is much less than using aspirin.
Clopidogrel is commonly used for inhibiting aggregation of platelets. The mechanism is that P2Y12 which is ADP receptor takes irreversible changes and selectively inhibits aggregation of platelets induced by ADP, and aggregation induced by collagen and thrombin are also can be inhibited. It is now widely accepted that in comparison with aspirin, clopidogrel is more effective. But it is believed that clopidogrel does not have advantages in other benefits for the authorities have not yet submitted a prove that clopidogrel plays better than aspirin. For those who have a contraindication to low-dose aspirin, clopidogrel (75 mg/d) is a good alternative drug for patients with high risk coronary cerebrovascular disease or peripheral vascular diseases.